US4144477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Long life incandescent switching system
Assignee: Combustion Engineering Inc
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Filing: 1977-07-14
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Granted: 1979-03-13
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Expires: 1997-07-14
Abstract
Abstract A supply and switching system for incandescent indicator lights is disclosed. A solid-state AC switch is used in conjunction with a current-limiting-transformer supply. The use of the current-limiting transformer protects the solid-state switch from the large current transients that are sometimes caused by failures in incandescent bulbs.
Inventors
- 👤 Favre E. Eaton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:09
CPC Classifications
H; H05; H05B; H05B39/00; H05B39/04; H05B39/08; H05B39/083
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
A switching and supply circuit for supplying power to a load which operates at a normal current level but is subject to occasional high current surges, the load having first and second sides, comprising: a. a current limiting transformer having at least one secondary winding with first and second terminals, the first terminal in electrical communication with the first side of the load; and b. a solid-state switch connected in series with the second terminal of the secondary winding and the other side of the load.
Claim 2
Dependent Claim
86 words
A switching and supply circuit for supplying power to a load which operates at a normal current level but is subject to occasional high current surges, the load having first and second sides, comprising: a. a current limiting transformer having at least one secondary winding with first and second terminals, the first terminal in electrical communication with the first side of the load; and b. a solid-state switch connected in series with the second terminal of the secondary winding and the other side of the load.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1, wherein the current-limiting transformer comprises a magnetic-shunt transformer.
Claim 4
Dependent Claim
12 words
The apparatus of claim 2, wherein the load comprises an incandescent bulb.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |